1. "Batman is, like, wicked smart." I'm not sure why the son of two genetically engineered scientists from an advanced alien race would be dumb. His intelligence almost certainly would be well past "genius" by any human standard.

2. "Batman can do anything with enough prep time." Give them both weeks to prepare some scheme. Superman could go on vacation the whole time, then need mere seconds to replicate or assemble something more advanced given his super speed.

There really is no conceivable way for Batman to beat him. The reality is, Superman makes the conscious decision every day to ALLOW Batman to exist and do what he does. Batman is an ant compared to him.